---
type: source
title: "When AI Writes the World's Software, Who Verifies It?"
author: "Leonardo de Moura"
url: https://leodemoura.github.io/blog/2026/02/28/when-ai-writes-the-worlds-software-who-verifies-it
date_published: 2026-02-28
date_archived: 2026-03-16
domain: ai-alignment
secondary_domains: [teleological-economics]
status: enrichment
processed_by: theseus
tags: [formal-verification, lean, ai-generated-code, proof-verification, trust-infrastructure]
sourced_via: "Alex Obadia (@ObadiaAlex) tweet, ARIA Research Scaling Trust programme"
twitter_id: "712705562191011841"
processed_by: theseus
processed_date: 2026-03-19
extraction_model: "anthropic/claude-sonnet-4.5"
claims_extracted:
- "formal verification becomes economically necessary as AI-generated code scales because testing cannot detect adversarial overfitting and a proof cannot be gamed"
---

# When AI Writes the World's Software, Who Verifies It?

Leonardo de Moura (AWS, Chief Architect of Lean FRO) argues AI-generated code is proliferating faster than verification can scale. Mathematical proof — not testing alone — becomes essential infrastructure.

Key evidence:
- Google: >25% of new code is AI-generated; Microsoft: ~30%. Microsoft CTO predicts 95% by 2030.
- Anthropic built 100,000-line C compiler using AI agents in 2 weeks for <$20,000
- "Nearly half of AI-generated code fails basic security tests"
- Poor software quality costs US economy $2.41T/year (CSIQ 2022)

Key arguments:
- Testing provides confidence but not guarantees. "A proof cannot be gamed."
- AI overfits test suites — Claude C Compiler "hard-codes values to satisfy the test suite" and "will not generalize"
- Supply chain attacks via poisoned training data can "inject subtle vulnerabilities into every system AI touches"
- Lean has become the de facto formal verification platform (AlphaProof, 200K+ formalized theorems, 5 Fields medalists)
- Morrison (Lean FRO) demonstrated AI-generated Lean implementation of zlib with mathematical proof of correctness
- "The barrier to verified software is no longer AI capability. It is platform readiness."

Directly relevant to [[formal verification of AI-generated proofs provides scalable oversight that human review cannot match because machine-checked correctness scales with AI capability while human verification degrades]].


## Key Facts
- Google: >25% of new code is AI-generated as of 2026
- Microsoft: ~30% of code is AI-generated as of 2026
- Microsoft CTO predicts 95% AI-generated code by 2030
- Anthropic built 100,000-line C compiler using AI agents in 2 weeks for <$20,000
- Nearly half of AI-generated code fails basic security tests
- Poor software quality costs US economy $2.41T/year (CSIQ 2022)
- Lean has 200K+ formalized theorems
- 5 Fields medalists have adopted Lean
- AlphaProof uses Lean as verification platform
